Hoisting mechanism



Nov. 13, 1934. H E, SCOTT 1,980,297

' HOISTING MECHANISM Filed July 6 1931 2 Sheets-Sheet l V Y v mvENToR i ATTORNEYS Nov. 13, 1934. H E, SCOTT 1,980,291

HoIsTING MECHANISM Filed July s, 1931 2 sheets-,sheet 2 Illllllllllllflllli INVENTOR f//WPY 45207-7' ATTORNEYS Patented Nov. 13, 1934 UNITED STATESv HOISTIN G MECHANISM Harry E. Scott, Cleveland Heights, Ohio, assignor to The Thew Shovel Company, Lorain, Ohio, a

corporation of Ohio 'Application July 6, 1931, Serial No. 548,776

Claims.

My invention relates to excavating and load handling machines commonly known as power shovels in which a rotatable super-structure carrying a boom is mounted upon a truck and,

i more particularly, has to do with the design and arrangement of cooperating parts in the driving and operating unit of such power shovel which uses a single source of power together with suitable gearing and friction clutches for transmitl0 ting power -for the various shovel operations and, specifically, relates to the load handling-part of the apparatus.

In ordinary constructions, the load handled by the power shovel is raised by means of a cable which has one of its ends dead-ended at some point on the boom or frame of the shovel and the other end passing around sheaves on the boom and framev and around a drum which is rotated in either direction or held against r0- tation in any preferred manner to raise,.lower,

or hold the load stationary.

One object of my invention is to provide a drive in either direction at both ends of the load handling cable independent of the force of gravity, Weight of the load, or amount of frictional resistance in the load handling mechanism.

Another object of my invention is to provide a device whereby it ispossible to obtain a slow speed or a slow rate of winding or unwinding at one end of the load handling cable and a higher rate of winding or unwinding -at the opposite end of the same cable by providing two separately driven drums, each independent of the otherin location, operation and control.

A further object is to 'avoid' changes in operat' ing gear and other parts of a standard power shovel, this being accomplished by providing an independent hoisting drum on the boom and ac-Y tuating this hoist from the same source of power as used for the other shovel operations without radical change in the operating mechanism..

A still further object is to provide for a more precise control of the load thanhas heretofore lbeen obtained.

Various other objects and advantageous features of my invention will be apparent from the following description, and one embodiment thereof may be seen in the accompanying. drawings wherein similar characters of reference designate correspending parts, and whereinz- Fig. 1 is a side view of an entire power shovel (the cab being omitted) constructed in accord'- ance with my invention and showing the arrangement of the entire mechanism; Fig. 2 is a fragdrive between the single power unit of the power shovel shown in Fig. 1 and a hoisting drum mounted on the boom thereof; and Fig. 3 is a diagrammatic view showing the operative relation between various shafts and the general driving arrangement therebetween.

Referring to the drawings, I have shown a power shovel similar to the one shown and described in Patent No. 1,698,748 to which reference vmay be had for details not described herein, in 66 which the principal parts of the shovel are the truck 1 upon which is rotatably mounted a driving assembly generally indicated by the reference numeral 2 and carrying a boom 3 equipped with suitable lines for raising and lowering a running hook or other grapple means 5. Generally speaking, these parts are well known in the art.

The driving assembly 1 includes a framecomprising essentially a sectional base, a pair of uprights 6 connected with the forward section 7 of 75 the base as by means of pins '9, supported by struts 10, and connected at the `top by a shaft 11 carrying sheaves over which pass suitable cables 12 leading to the boom. Likewise, the driving assembly includes a rear section 13, connected 30 to the forward base section in any well known ,manner and supported by tie rods 14 leading to the uprights 6. Between these uprights 6 are mounted the driving shafts of the mechanism carrying suitable clutches and drums, and rear- '35 ward of the uprights is mounted a vpower source 15 such as the internal combustion engine diagrammatically illustrated.

A shaft 16 is mounted between the uprights 6, and projects beyond one of them as shown in Fig. 9o 3 'to carry a sprocket v1'! diagrammatically illustrated which is in driven connection by means of a driving chain or belt 18 with a driving pinion on the power unit l5. A pinion 19 forms a part of the sprocket 17 and is rotatable therewith 95 upon the shaft 16. Moving directly with this pinion, and carried by shafts mounted between the uprights 6, are gears 20, 21 and 22 upon the crowd and travel shaft. 23, the swing shaft 24, and the load hoist drum shaft 25, respectively. l

The load hoist drums 26 mounted on the sha 25 are controlled by the usual friction clutch and brake devices conventionally illustrated as at 27, the swing mechanism is controlled by the left and right hand clutches 28, and the crowd and travel 105 shaft 23 is controlled by the clutch'29 for slow speed operation in one direction and clutch 30 through gears 3l, 32 for high speed operation in the 'opposite direction. Jaw clutches 33 and 34 am; gear 35 slidable on a jack shaft as by means 11 y 27, whereby upon release of either of the clutches 27, the corresponding drum can be maintained stationary. To swing the boom to right or left, the proper clutch 28 is engaged which actuates a pinion 41 that has planetary relation with a fixed gear 42, the drive being from the pinion "19, through the gear 21, shaft 24, clutch 28, bevel pinion 43, and bevel gear 44 to the pinion 4l.

For hoisting the boom 3, or traveling under low speed conditions, the proper jaw clutch 34 is engaged whereupon by engagement of the clutch 29 the shaft 23 is set in motion to produce the desired result and for lowering the boom, or traveling at high speed, the clutch 29 is released and the clutch 30 is engaged whereupon drive of the shaft 23 is-effected from the pinion 19, through the gear 21, shaft 24, gear 31, and gear 32. The boom hoist is controlled by engagement of the gear 35 with the gear 32, such engagement being effected by the shifting collar 37.

In accordance with my invention, suitable means have been provided for obtaining a positive drive at both ends of a cable 45 which passes over a double sheave 46 at one end of the boom 3 and downwardly to and around the running hook or other grapple means 5. As usual, one end of this cable is wound around the load hoist drum 26. However, instead of having the other end of the cable 45 dead-ended at some point on the l.mechanism as has heretofore been customary, my invention contemplates the provision of a drum 47 mounted on the boom 3 and around which that usually dead-ended end of the cable 45 is wound after forming a loop in which the running hook or other grapple means is supported and passing upwardly over the double sheave 46 on the boom, the drum being rotatable on a shaft 48.

4The drum 47 and shaft48 are drivenby the same power unit l5 which drives the load hoist drums 26 in the `manner hereinbefore described -by means of the chain 39 driven by the sprocket 38` which passes around a sprocket 49 on a shaft 50 that is rotatably mounted in axial alignment with the pivot point between the boom 3 and the forward section 7 of the frame as shown in Fig. 1. Sprocket 38 may be provided with an automatic brake which holds the drum 47 stationary whenthe clutch 33 is disengaged, although this is not essential. This shaft 50 also carries a bevel gear 51 that meshes with a bevel gear 52 suitably mounted on a shaft 53 suitably supported in bearings 54 in a housing carried by the boom 3. Shaft 53 carries a worm 55 which meshes with a worm gear 56 rigidly mounted on the shaft 48 which carries the drum 47. Thus, it will be seen that the drum 47 to which one end of the cable 45 is attached may be rotated to wind or unwind the cable by engaging the jaw clutch 33. An operative driving connection isA provided for in this manner between the hoist drum carried by the boom and the same power unit as operates the usual load hoist drum and remainder of the mechanism by the axial alignment of the shaft 50 with the pivot oi.' the boom whereby the boom may be raised or lowered without the bevel gear 52 becoming disengaged from the bevel gear 51 as is clearly shown by the dotted lines in Fig. 2.

With the above construction, I have provided an apparatus wherein the one end of the load handling cable that is usually dead-ended as has heretofore been customary is positively driven. Thus, both ends of the cable are driven, one by means of a high speed drum and the other by a low speed drum. Such construction provides drive for the cable at both ends thereof, independent at one end of the force of gravity, weight in the hoist mechanism. Such drive is provided for withoutnecessitating radical changes in, the operating mechanism. An absolutely precise control of the load being handled is assured in that the load may be hoisted or lowered at any desired rate of speed and may be jockeyed into position after it has reached the desired height.

Such precise control is secured because of the character of the drive to the opposite ends of the hoisting cable. Drum 26, at one end of the cable, is the usual hoisting drum, operating at relatively high speed and driven by the usual friction clutch mechanism to wind up .the cable and controlled by the usual brake mechanism to release it. With this drum alone the load may be hoisted or lowered rapidly to approximately the desired position. More precise control of the position of the load is secured by operation of the Supplemental drum 47. This drum, attached' to the other end of thecable, is driven by clutch and reversing mechanism hereinbefore described, and also by the worm 55 and wormgear 56,whichworm gear mechanism produces very material speed reduction and also constitutes a one-way driving connection adapted to transmit power from the power source to. the drum but is inoperative and hence self-locking against rotation in the opposite direction when the clutches are released. In other words, the clutch mechanism, reversing -of the load, or amount of frictional resistance mechanism,and worm gear drive to the drum 47 4 constitute a system by which, at low speed, the load may be accurately placed at the desired level by a positive drive in either direction, with the assurance that when the drive is disconnected, by opening the clutch, the load will remain in the position towhich it has been adjusted. Moreover, the positive drive to drum 47 enables the load to be-more accln'ately adjusted than is possible by way of the usual friction clutch and brake control, such as is employed upon the drum 26.

What I claim is: a `1. Apparatus of the class described, comprising `a frame, a load hoisting mechanism carried by which one end of said cable is wound, said drum being carried by said frame and having operative connection with said power unit, means for positively driving the other end of said load hoisting..

cable to raise or lowera load, said means including a rotatable drum about which said other end of the cable is wound, said last named drum being carried by-said boom, and an operative connection between said last named drum and said power unit, including means for positively driving the drum selectively in either direction, whereby the same power unit may be effective to drive both of said drums and the boom carried drum may be positively rotated in. either direction, and means for selectively controlling the operation of said drums, whereby they may be driven separately or simultaneously.

2. Apparatus of the class described comprising, a frame, load hoisting mechanism carried by said frame and including a boom, sheaves on said boom, a power unit, a `load hoisting means including a double-ended cable `passing over the sheaves on said boom, means for driving one end of saidcable to raise or lower a load including a rotatable drum about which that end of said cable is wound, said drum being carried by said frame and having operative connection with said power` unit, means for positively driving the other end of said cable to raise or lower the same load, said means including a drum about which said other frame and including a boom, sheaves on said.

boom, a power unit, a load hoisting means including a cable passing over said sheaves and forming a loop at one side thereof, a running load engaging means carried by said cable in the loop thereof, means for driving one end of said cable to raise or lower ,a load including a rotatable drum about which that end of said cable is wound,.said drum being carried by said frame and having operative connection with said power unit, means for positively driving the other end of said cable to raise or lower thel same load, said means irl-- cluding a drum different insize from said first named drum about which the other end of said cable is wound, said last named drum being carried by said boom, an operative connection beL tween said last named drum and said power unit, including means for positivelydriving `the drum selectively in either direction and at different speeds, whereby the same power unit may be eiective to drive both of said drums, and means for selectively controlling the operation of said drums whereby they may be driven separately or simultaneously or at different speeds.

4. Hoisting mechanism, comprising a frame, a boom carried thereby, a two-end `hoisting cable having a load carrying loop depending from the boom, and operating means therefor, comprising a winding drum for one end of said cable provided with the usual high speed driving and friction brake mechanism, a supplemental winding drum for the other end of said cable, and positive low speed driving means therefor including clutch mechanism and a worm and worm gear connection adapted to drive from the power source to the drum`but inoperative and hence self-locking against drive in the reverse direction.

5. Hoisting mechanism of the character described'in claim 4, in which the driving means for the supplemental winding drum includes reversing mechanism. l HARRY E. SCOTT. 

